When Fuel X burns in air, it forms carbon dioxide and water. Fuel Y does the same. What might X and Y be?
- A$X=\text{C},\ Y=\text{H}_2$
- B$X=\text{C},\ Y=\text{C}_8\text{H}_{18}$
- C$X=\text{CH}_4,\ Y=\text{H}_2$
- D$X=\text{CH}_4,\ Y=\text{C}_8\text{H}_{18}$